Since 1900, approximately 96% of the fires in sprinklered buildings have either been extinguished by sprinklers or held in check until manual fire fighting equipment arrived. The resulting savings in both life and property has been immeasurable. Yet, as business and industry continues to expand, so does the likelihood of catastrophic fire damage. The response to this overall increase in susceptibility of loss from fires has largely been to concentrate on developing newer and more effective sprinkler systems.
The sprinkler system, composed of a network of risers, cross mains, and branch lines all connected by a main line to the building's water supply, activates when one or more of the temperature sensitive sprinkler heads opens. Essentially, two situations may arise.
The first case occurs when there is in fact no fire, and the sprinkler system has been actuated either by a defect in or an external disturbance to the system. The resulting unnecessary water damage which may occur should be minimized through an immediate response by an experienced maintenance personnel.
The second case which involves a real fire is the greater concern. The event of an actual fire demands that the automatic sprinkler system perform its four basic functions: detect the fire, call attention to the fire condition, control the fire and keep it from growing, and extinguish the fire. In this situation, timely combat of the fire by experienced firemen may save both invaluable lives and costly property.
Therefore, in either case, one of the most critical functions of the alarm system is the prompt notification of concerned parties. This notification invariably begins as an electric signal which results from the activation of a water flow alarm device located in the riser or other pipe of the sprinkler system. The design of the water flow alarm usually includes a check valve or an alarm check valve and a pressure switch or a vane alarm which lifts a paddle upon the flow of water through the system, thereby mechanically activating an electric switch and thus initiating the electric signal.
If the fire sprinkler system was inadvertently set off, the warning signal allows the sprinkler system to be shut off before massive water deprivation occurs. If the sprinkler system has been activated by a fire, immediate warning of the fire and summon of fire extinguishing personnel results.
However, a malfunctioning water flow alarm device will prevent the successful notification of monitoring personnel. Moreover, problems such as an obstruction in the water line or an inadequate water supply may not only hinder emergency notification of monitoring individuals, but may also result in a less than optimal flow of water through the sprinkler heads themselves. The consequences of any defect in the sprinkler system could very well be disastrous.
Therefore, efforts have been made in the past to test the integrity of automatic sprinkler systems to assure that they will always successfully perform their functions. While one method to test the system would be to set off one of the sprinkler heads themselves, such a procedure would be complicated, time consuming, and more than likely, saturating.
The most popular method to test automatic sprinkler systems simulates an actual water discharge through a sprinkler head by initiating a water flow through the system at an alternate test location. In order to simulate a real water discharge as closely as is possible, this water flow is not greater than what would be the actual water flow through an open sprinkler head. In this manner, the water flow signal alarm can be activated to produce an electric signal while not disturbing any of the temperature sensitive elements in the sprinkler heads.